Yes, ICG issues population reports. I did not see any at the show.

"Who are the "experts in the chip industry" they are using to grade or authenticate chips submitted for slabbing?"

Henry is a good guess but only a guess.
I also guess the authors of the "Official" book.
I have other Suspicions at this time. Nor ready to post names, YET.

ICG is closely guarding the names and I can't say that I blame them.